Table 2.
Psychometric properties of the measures used in this study
| Reliability | Item discrimination of each measure a | Model fit of confirmatory factor analysis (CFA) d | |||||||
|---|---|---|---|---|---|---|---|---|---|
| α | t b | p | χ2 | df | CFI | RMSEA | 90%CI | SRMR | |
| 1. Knowledge about the COVID-19 | 0.91 | [−63.90, −45.57] | < 0.001 | 386.87 | 24 | 0.99 | 0.06 | [0.052, 0.062] | 0.02 |
| 2. Perceived severity | 0.84 | [−65.61, −52.08] | < 0.001 | 62.06 | 3 | 1.00 | 0.07 | [0.052, 0.080] | 0.02 |
| 3. Perceived controllability | 0.91 | [−93.59, −49.78] | < 0.001 | 135.78 | 17 | 1.00 | 0.04 | [0.033, 0.045] | 0.01 |
| 4. Emotional and behavioural reactions | |||||||||
| Negative emotion | 0.91 | [−59.46, −34.28] | < 0.001 | 192.48 | 8 | 0.99 | 0.07 | [0.062, 0.080] | 0.02 |
| Positive emotion | 0.97 | [− 115.87, − 114.46] | < 0.001 | e | e | e | e | e | e |
| Sleep problem | 0.91 | [−42.78, −29.82] | < 0.001 | 24.11 | 2 | 0.99 | 0.05 | [0.033, 0.067] | 0.01 |
| Aggression | 0.90 | [−60.09, −22.67] | < 0.001 | f | f | f | f | f | f |
| Substance use | 0.91 | [−27.75, −15.85] | < 0.001 | f | f | f | f | f | f |
| Mobile phone use | – | −101.18 c | < 0.001 | f | f | f | f | f | f |
| 5. Social participation | 0.79 | [− 70.45, −47.41] | < 0.001 | 23.71 | 3 | 1.00 | 0.04 | [0.025, 0.054] | 0.01 |
| 6. Precautionary behaviour | 0.92 | [−55.19, −33.11] | < 0.001 | 2950.96 | 121 | 0.96 | 0.07 | [0.069, 0.073] | 0.08 |
a: The ability of each item in a measure/dimension to differentiate the high (top 27%) and the low (bottom 27%) total score of that measure/dimension was examined
b: T-values of the comparison between the high and the low total score groups in the item discrimination tests are presented as a range. For instance, the measure of “Knowledge about the COVID-19” consists of 11 items; the range represents the t values of the comparison for these 11 items
c: The “mobile phone use” dimension has only 1 item and thus no range is presented
d: Some residuals are correlated when we fit the CFA models for some measures/dimensions
e: This dimension has 3 items and thus the CFA model is a saturated model (i.e., χ2 = 0.00, df = 0.00, CFI = 1.00, RMSEA and SRMR = 0.00)
f: Each of these dimensions has less than 3 items and thus CFA is not applicable